Sedona, AZ
Ryan Conlon
Sedona, AZ
Vanessa Lyons
SEDIMENTATION AND SEDIMENTARY ROCKS
CHEMICAL SEDIMENTARY ROCKS
Typically consist of interlocking minerals crystallizing
upon precipitation from seawater.
LIMESTONE
Composed of Calcite (CaCO3)
Comprise 10-15% of all sedimentary rocks.
CaCO3 precipitates in warm water.
SEDIMENTATION AND SEDIMENTARY ROCKS
CHEMICAL SEDIMENTARY ROCKS
LIMESTONE
CaCO3 precipitates in warm water.
Related to the solubility of CaCO3.
CO2 content goes down as water temperature rises.
CaCO3 is more soluble at cold temperatures in ocean.
Agitation of water also drives off CO2 making CaCO3
precipitate.
Aquatic plants remove CO2 so more CaCO3 precipitates.
Most chemical carbonates precipitate when all 3 work.
SEDIMENTATION AND SEDIMENTARY ROCKS
CHEMICAL SEDIMENTARY ROCKS
LIMESTONE
Grand Bahamas Banks
Area of oolite production
SEDIMENTATION AND SEDIMENTARY ROCKS
CHEMICAL SEDIMENTARY ROCKS
EVAPORITES
Precipitate from sea water.
Include
Gypsum
Halite
Sylvite
Limestone
Dolores River
Paradox Valley, CO
SEDIMENTATION AND SEDIMENTARY ROCKS
CHEMICAL SEDIMENTARY ROCKS
EVAPORITES
Typically found only in arid climates.
White Sands National Monument, NM (gypsum)
Subsurface salt deposits found in
Colorado-Utah
Michigan
Gulf Coast
SEDIMENTATION AND SEDIMENTARY ROCKS
CHEMICAL SEDIMENTARY ROCKS
Paradox Valley, Colorado
White Sands
National Monument, NM
SEDIMENTATION AND SEDIMENTARY ROCKS
CHEMICAL SEDIMENTARY ROCKS
EVAPORITES
Salt Domes
SEDIMENTATION AND SEDIMENTARY ROCKS
CHEMICAL SEDIMENTARY ROCKS
DOLOMITE
Composed of the mineral dolomite (Ca,Mg(CO3)2).
Similar to limestone in appearance.
Not really exactly sure how it is deposited.
SEDIMENTATION AND SEDIMENTARY ROCKS
CHEMICAL SEDIMENTARY ROCKS
CHERT
Composed largely of silica (SiO2).
Most are inorganic.
Precipitate from SiO2-rich waters.
Can occur as nodules.
Cavities in limestone or dolomite fill with silica.
SEDIMENTATION AND SEDIMENTARY ROCKS
ORGANIC SEDIMENTARY ROCKS
Derived from living organisms.
Principally limestone, chert and peat (some coals).
Radiolarian
Diatom
SEDIMENTATION AND SEDIMENTARY ROCKS
ORGANIC SEDIMENTARY ROCKS
LIMESTONE
Composed of Calcite (CaCO3).
Originate in warm, marine environments.
Organisms extract Ca+2 and CO2 from water to make
skeletons.
Upon death, skeletal material accumulates forming
LIMESTONE.
Most limestones form in shallow waters on continental
shelves in equatorial regions.
Can also form in deep water.
SEDIMENTATION AND SEDIMENTARY ROCKS
LIMESTONE
Fossiliferous Limestone
SEDIMENTATION AND SEDIMENTARY ROCKS
LIMESTONE
Lithographic Limestone
or Micrite
SEDIMENTATION AND SEDIMENTARY ROCKS
LIMESTONE
Coccolith
Chalk
SEDIMENTATION AND SEDIMENTARY ROCKS
CHERT
Can also be produced by organisms.
From skeletons of radiolarians and diatoms.
Radiolarians
Diatoms
SEDIMENTATION AND SEDIMENTARY ROCKS
PEAT
An organic sedimentary rock formed from plant
debris.
Accumulates in O2-poor swamps and bogs.
With addition of heat and pressure can form coal.
Peat
Lignite
Bituminous
Anthracite
SEDIMENTATION AND SEDIMENTARY ROCKS
North American Coal
Developed in two time periods
Pennsylvanian ~ 280 million years ago.
Formed mostly in Appalachian region.
Cretaceous-Tertiary ~ 75 million years ago.
Formed mostly in Rocky Mountain region.
SEDIMENTATION AND SEDIMENTARY ROCKS
North American Coal